shaners90lxhatch

I spend the majority of my time in the 5.0 forum, so apologize if my the spontaneity of my comments is a disturbance. I would just like to let new stang owners in on some info. If you experience any type of hesitations or power losses on acceleration, especially after a long cruise - have your dealer check it out. There is an updated fuel pump that is designed to prevent cavitation (localized boiling that will cause the formation of tiny bubbles. These bubbles collect in the primary fuel filter and will be sucked up from time to time giving hesitations). This only applies to '05's and early build '06's. Also be careful what modifications you leave on in the event your car is ever worked on by the dealer. Like Saleen and Roush vehicles with powertrain modifications, your powertrain warrany will be voided if a failure is in any way attributable to the modification. This basically includes everything except cold air intakes (with well kept filters) and exhuast that is extremely similar to stock. PCM programs are getting easier to identify and will cause problems as well. The problem you have filling your fuel tank is being considered a characteristic until 2009 and will not be addressed further than a filler neck adjustment and an updated fuel tank (that do not completely resolve the issue). The best hope you have is to fill the tank only when it reaches 1/2 or less. The noises of your transmission are normal and will worsen with age. Best to just accept it. Has there ever been a mustang with a decent 5 speed? Changing your oil is clutch in keeping your engine mechanically sound. This is obvious but moreso with the 3v design. The VCT or variable cam timing system is extremely dependent on the cleanliness of your oil. Small oil feed passages will easily clog up and create anything from noise to driveability problems, check engine lights and maybe engine damage. Have your spark plugs removed somewhat often and do NOT drive your mustang like a grandmother. The 3v design has a problem with the unique style of spark plug that is required - it likes to break off in the cylinder head. This is an ongoing problem with the 5.4 3v in the trucks and the 4.6 3v is absolutely no different in design operation. The difference in use is what makes this less common in the Mustang. You have a 50% chance of this being minor enough to address without cylinder head removal (thousand dollar + job) but more than likely it will require more than the dealer and a special tool recently designed by Rotunda to remove it. Just like with the oil quality thing, ask a 5.4 3v truck owner. The plugs break off in the head because the center portion of the plug is extended and unusually exposed to the combustion event. This causes carbon to build up between the plug and the head effectively fusing the two together. That's about all the latest on the 4.6 3v powertrain. Aside from a few connecting rod issues for early '06 builds (which you should have experienced by now if you had them) I have pretty much covered the important stuff.... I will post any other helpful goodies should they arrive.
ooops, my lack of introduction..... Let's just say that I have extremely credible sources of information and share it in the spirit of good will. I feel caring owners should know what they are paying for and use the information not as a way to inspire you to "get new parts" but as a way to prevent the need for such. Should you not be experiencing any of these issues, you need not be concerned. BTW, ditch the K&N air filter. It tricks the cars computer into thinking it is consuming less air than it is, resulting in a lean condition. Your computer corrects this by adding more fuel and effectively reducing your fuel economy and overall performance. It will contaminate the MAF sensor as well. It truly is nothing more than a good looking waste of money. Good luck, have fun and buy blue baby!

gtmachine

So your saying the best way to prevent the plug tip breaking off into the cylinder is to frequently take it out on the highway or at least run through the gears at wot to burn off any built up carbon?

shaners90lxhatch

That's basically correct. Carbon will build naturally but any method of prevention should be considered given the cost of cylinder head removal on a brand new car such as this. Allow your car to reach full operating temperature every time it is run. Do not frequently crowd the throttle in low gear and not give it a chance to rev. Stay out of high load, low RPM conditions as much as possible. Take it out and knock the cobwebs out of it every now and then, after all it is a sports car. Use reputable fuel. People under estimate the likelihood of getting bad gas. It happens much more often than you think, chances are you have been a victim and never even knew it. Use fuel from newer stations that do a lot of business. ONLY put 87 octane in your mustang unless it is supercharged. Higher octane fuel than is needed will facilitate carbon deposits. And, finally remove them (plugs) and clean/replace them every 10-15k miles. You will have to request the dealer do this (better in 3/36 than out of it) or buy a special socket to remove them) It may seem over zealous but I have seen many 5.4 3v's with 20k miles need both heads off. You can imagine how happy the guy at 37K miles is! BTW, I forgot to mention that you already have the updated fuel tank if your car was build 5/05 or sooner.

doode

In your opinion its better to have the dealership pull and clean the plugs?
How much would they charge for this if i do it yearly?
Whats standard shop rate / time to re-re 8 plugs?

TIA

shaners90lxhatch

A dealer that knows what they are doing, yes. More often than not the dealer only takes precautionary meausures after one has begun to break off. If you buy the socket youreself, just allow a really good penetrant like (buy this or don't attempt it) KROIL also known as aerokroil. or PB blaster. Break them loose with a 1/8 turn and fill up the plug wells about 1/3 of the way. let it sit until the penetrant has done it's job. Like I said, this does not seem to be a problem with the 4.6 3v as of yet, but considering it is identical in design as the truck engine that does have this problem, it is very likely to be in the future.

viking396

No problem for the majority of Mustang owners!

wildabouthorses

Every once in a while the gas pump won't start filling the car or it only fills it partly and cuts off not to let you pump more gas. I told my hubby to try the upside down pump handle deal when that happens and it will fill it completely. He didn't know about that trick and the problem happened to him just this past week when he tried filling the car up. It works everytime for me when I get the pump problem and that doesn't happen often at all. I have an 05 convert V6. I can honestly say I've had to turn the handle upside down probably 3 times in the 13,000 miles the car has. I know my hubby hasn't done it yet because he didn't know about that trick. He told me he filled the car just last week only to find when he drove away that the car was really only 3/4's full. He thought we had a weird problem that just developed.


What is the MAF sensor? My hubby has been complaining the car isn't doing as good gas milage wise at it first did. Now you have me wondering if the K&N filter he put in there is the culprit! Will just switching back to the Mustang's stock air filter correct this problem?

dmhines

I'm confused about the K&N filter comment .... does this apply to all CAI's ... I just happen to the have a K&N CAI ... or are you talking about the K&N standard replacement filters for the factory airbox?

shaners90lxhatch

Your entire air induction system is designed around the MAF (Mass Air Flow sensor). This sensor measures the ammount of air the engine takes in and is the most influential input to the cars computer when it comes to fuel regulation. It's accuracy is extremely dependent on the poper location of the sensor and the diameter/shape of the intake tubing. This engine will not benefit from a more streamline intake system as the originial is not restrictive (only much more quiet than an aftermarket). Likely the K&N filter is the source of your fuel economy reduction. You want the best fuel economy and the least ammount of fueling issues? Stick with the stock induction. Any modification to the inlet system runs a high risk of fueling issues due to MAF contamination. The benefits attainable with 99% of the aftermarket intake systems are greatly outweighed by the risk of issues. BTW, dealers will likely not warrant MAF replacement if an aftermarket air filter is found.

dmhines

What do you say to the folks who have verified on a Dyno that just replacing the stock intake with a CAI shows 7 RWHP gains? Again ... this is not seat of pants stuff ... but actual dyno runs ...